1. Field of the Invention
The present invention relates to interactive computer systems, and in particular to a method and apparatus for facilitating wireless, full-body interaction between a human participant and a computer-generated graphical environment including textual data.
2. Description of Related Art
So-called “virtual reality” (“VR”) systems enable users to experience computer-generated environments instead of merely interacting with them over a display screen. Such systems typically require the user to don goggles, through which he or she perceives the virtual environment, as well as sensors that encode the user's gestures as electrical signals. The user reacts naturally to the changing virtual environment, generating signals that the computer interprets to determine the state and progress of the presented environment.
In order to encode a sufficiently board spectrum of gestures to facilitate natural interaction, VR systems ordinarily require the user to wear, in addition to the goggles, at least one “data glove” to detect hand and finger movements, and possibly a helmet to detect head movements. Full-body systems, which encode movements from numerous anatomical sites to develop a complete computational representation of the user's overall body action, require many more sensors; however, such systems, would be capable of projecting the user fully into the virtual environment, providing the user with greater control and a heightened sense of participation ideally suited to interactive simulations.
Unfortunately, numerous practical difficulties limit the capacity of current VR systems to achieve this goal. The nature of the interaction currently offered, even with full-body sensor arrays, is limited. The computational demands placed on a system receiving signals from many sensors can easily overwhelm even large computers, resulting in erratic “jumps” in the visual presentation that reflect processing delays. Moreover, no matter how many sensors surround the user, that cannot “see” the user, and therefore cannot integrate the user's true visual image into the virtual environment.
Economic and convenience factors also limit sensor-type VR systems. As the capabilities of VR systems increase, so do the cost, awkwardness and inconvenience of the sensor array. The sensors add weight and heft, impeding the very motions they are intended to detect. They must also ordinarily be connected, by means of wires, directly to the computer, further limiting the user's movement and complicating equipment arrangements.
In order to overcome the limitations associated with sensor-based VR systems, researchers have devised techniques to introduce the user's recorded image into a virtual environment. The resulting composite image is projected in a manner so that it may be viewed by the user, enabling the user to observe his or her appearance in and interaction with the virtual environment.
Three such approaches include the VideoPlace system (see, e.g., M. Krueger, Artificial Reality II (1991) and U.S. Pat. No. 4,843,568), the Mandala system (see, e.g., Mandala VR News, Fall/Winter 1993; Vincent, “Mandale: Virtual Village” and Stanfel, “Mandela: Virtual Cities,” Proceedings of ACM SIGGRAPH 1993 at 207-208 (1993)), and MIT's system disclosed in U.S. Pat. No. 5,563,988. Unfortunately, these systems exhibit various limitations. For example, Krueger's VideoPlace requires a special background and ultraviolet lamps, and extracts and represents only the user's silhouette. The Mandala system can integrate the user's full image within the virtual environment it creates, but requires a chroma-key blue background. The system developed by MIT provides a 3-Dimensional spatial video interaction with a user and is directed to detecting and analyzing gestural information of the user to cause predetermined responses from graphically generated objects within the virtual environment (e.g., if a virtual user pets a graphically generated dog within the virtual environment, the dog may wag its tail). Regardless of the systems, all of the above-described VR systems employ complex video analysis and tracking techniques to detect and follow the boundaries of the user's image within the virtual environment.
The disclosure of U.S. Pat. Nos. 5,563,988 of Maes et al, and 4,843,568 of Krueger et al. are hereby incorporated by reference as if set forth in their entirety herein.
Applicant has recognized the need for a simple 2-dimensional video-generated real-time interaction system wherein text data is easily introduced into a virtual environment, as viewed on a monitor or on a projection screen. The inputted text data is manipulated in the virtual environment by video representation of a human participant (a “virtual user”). Through movements in the real world, the human participant or virtual user freely interacts with the inputted text data in the virtual environment as the human participant (and other people watching the monitor or projection screen) absorbs the teachings of the text data as he or she interacts with the text data in the virtual environment.